The present invention generally relates to magnetic recording and/or reproducing elements for recording and/or reproducing apparatuses, and more particularly to a magnetic recording and/or reproducing element which is suited for use in a so-called electronic camera which records and reproduces a video signal obtained by an image-pickup.
A so-called electronic camera which records a video signal on a flexible hollow cylinder shaped magnetic recording medium (hereinafter simply referred to as a magnetic drum), was previously proposed in a U.S. patent application Ser. No. 436,442 entitled "RECORDING AND/OR REPRODUCING APPARATUS" and filed Oct. 25, 1982, (now U.S. Pat. No. 4,567,535) in which the assignee is the same as the assignee of the present application. This electronic camera was proposed as a potential replacement of the conventional still picture camera using an optical 35 mm film. The electronic camera has a main camera body which is substantially the same in size as a main camera body of a normal 35 mm single-lens reflex camera. The magnetic drum is rotated at a rotational speed of 3600 rpm within the main camera body, and a video signal obtained by picking up an image by a solid-state pickup element such as a charge coupled device (CCD) is magnetically recorded on the magnetic drum by a magnetic recording and reproducing element. The magnetic recording and reproducing element records the video signal at a rate of one field per revolution of the magnetic drum, and is successively moved along a longitudinal direction of the magnetic drum.
In such an electronic camera, circular tracks which are formed on the peripheral surface of the magnetic drum have an extremely small track width of under 5 .mu.m, in order to obtain a large recording capacity with the small magnetic drum. Hence, a gap which is formed in the magnetic recording and reproducing element must be set to the extremely small track width of under 5 .mu.m.
In the magnetic recording and reproducing element which has the gap with the extremely small track width, the gap is formed between two ferromagnetic layers which are extremely thin and oppose each other at respective edges thereof. The ferromagnetic thin layers have a thickness which is in correspondence with the track width. Each ferromagnetic thin layer is sandwiched between non-magnetic support blocks which are abrasion proof. A part of such a magnetic recording and reproducing element, which makes contact with the rocording medium, has a relatively large area and is not subjected to a special processing.
When the magnetic recording and reproducing element having the construction described above is used in the electronic camera, a predetermined contact part including the gap of the magnetic recording and reproducing element makes contact with an arcuate surface part of the peripheral surface of the magnetic drum when the magnetic recording and reproducing element assumes a regular position. However, when the position where the magnetic recording and reproducing element makes contact with the peripheral surface of the magnetic drum deviates in a circumferential direction from the regular position, a part of the magnetic recording and reproducing element other than the predetermined contact part makes contact with the peripheral surface of the magnetic drum, and the gap is no longer in contact with the peripheral surface of the magnetic drum. Because the magnetic recording and reproducing element is in contact with the peripheral surface of the magnetic drum cartridge over a relatively large area, a distance between the gap and a position where the magnetic recording and reproducing element actually makes contact with the peripheral surface of the magnetic drum increases as the deviation from the regular position increases. As a result, a separation between the gap and the peripheral surface of the magnetic drum increases as the deviation from the regular position increases.
Consequently, the known spacing loss becomes large to such an extent that the spacing loss is not negligible, and the signal-to-noise (S/N) ratio of the reproduced signal becomes deteriorated. In a case where the track width is extremely narrow as described before, the magnetic energy contained in the tracks is small, and the deterioration in the S/N ratio of the reproduced signal due to the spacing loss becomes a serious problem.